arch/arm64/kvm/guest.c in KVM in the Linux kernel before 4.18.12 on the arm64 platform…
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
Summary
arch/arm64/kvm/guest.c in KVM in the Linux kernel before 4.18.12 on the arm64 platform mishandles the KVM_SET_ON_REG ioctl. This is exploitable by attackers who can create virtual machines. An attacker can arbitrarily redirect the hypervisor flow of control (with full register control). An attacker can also cause a denial of service (hypervisor panic) via an illegal exception return. This occurs because of insufficient restrictions on userspace access to the core register file, and because PSTATE.M validation does not prevent unintended execution modes.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 4.18.12 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* | 14.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* | 16.04 | Vulnerable | Canonical |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.18.12 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* Versions 14.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* Versions 16.04 Vulnerable ·Canonical
Remediation
Red Hat 1 advisory
- RHSA-2018:3656 Released 2018-11-26 · Red Hat rating Importantkernel-alt security and bug fix update
- Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) kernel-4.14.0-115.2.2.el7a, kernel-abi-whitelists-4.14.0-115.2.2.el7a, kernel-alt-4.14.0-115.2.2.el7a +9
- Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) kernel-debug-devel-4.14.0-115.2.2.el7a, kernel-tools-libs-devel-4.14.0-115.2.2.el7a
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) | Fixed | RHSA-2018:3656 |
| Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) | Fixed | RHSA-2018:3656 |
Not affected: 5 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise MRG 2
Timeline
- 2026-10-02 Threatist record created from CVE-2018-18021
- 2026-10-03 Alias added: GHSA-6vp5-5gv4-mcqp
References
Patch 6
- https://github.com/torvalds/linux/commit/2a3f93459d689d990b3ecfbe782fec89b97d3279
- https://www.openwall.com/lists/oss-security/2018/10/02/2
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.12
- https://github.com/torvalds/linux/commit/d26c25a9d19b5976b319af528886f89cf455692d
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2a3f93459d689d990b3ecfbe782fec89b97d3279
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d26c25a9d19b5976b319af528886f89cf455692d
Sources
- CVE-2018-18021 · CVE Program
- CVE-2018-18021 · NVD
- FIRST EPSS
- GHSA-6vp5-5gv4-mcqp · GitHub Advisory Database · CC BY 4.0
- CVE-2018-18021 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences